Issaquah residents can learn to tackle noxious weeds

King County’s least-wanted offenders can be found in open spaces, and along roads and creeks. The invasive and noxious weeds can damage natural habitats and economic resources.

The county is offering a class and workshops throughout the spring and summer to help property owners find and control the rogue invaders.

The least-wanted list includes plants, such as garlic mustard.

Discoveries of large garlic mustard infestations in the Coal Creek Natural Area in Bellevue and along the Cedar River last year raised concerns. Before, garlic mustard had been primarily limited to a few Seattle parks.

The weed, a fast-spreading biennial introduced to North America from Europe, moves quickly into forests and out-competes native understory species.

County Noxious Weed Program manager Steven Burke is asking for the public’s help in locating other infestation sites. Find garlic mustard photos and information are on the county’s noxious weed website and report discovered weed sites.

The county program is part of a statewide effort to detect and respond to noxious weeds. In order to help protect the state’s resources, the Washington State Noxious Weed Control Board adopts a statewide noxious weed list each year. Then, each county’s weed board then adopts a noxious weed list to establish the weeds in need of control by property owners and public agencies.

In King County, another high-priority target is the massive plant called giant hogweed. The weed is not only invasive, but produces a toxic juice that causes painful, watery blisters and burns on contact.

Like the name implies, giant hogweed has leaves up to 5 feet wide and a central flowering stem that reaches 15 feet, topped by a sizable umbrella-shaped flower-head, stretching 2 feet across.

The county’s noxious weed hunters have located more than 1,000 giant hogweed sites since 1996.

“By watching for new sites, returning to known sites every year, and helping landowners control it where needed, we have been able to keep giant hogweed from spreading and we are hopeful that it can be eradicated someday,” Burke said.

The hardest part of fighting uncommon noxious weeds, such as giant hogweed, is finding them. Burke said park users, homeowners and neighbors report many new sites of giant hogweed and other noxious weeds each year.

Invasive knotweed – a tough invader responsible for wreaking havoc along streams and rivers — is another concern.

The county’s Noxious Weed Program is offering a free class on invasive and noxious weeds from 6:30-8:30 p.m. June 7 at the Kent Regional Library.

The county also plans to bring information about noxious weeds to the Issaquah and Sammamish farmers markets. The display comes to the Issaquah market June 11 and to the Sammamish market June 15.